Tractor



FIG. 1 is a front perspective view of a tractor showing our new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a front view thereof; and,

FIG. 8 is a rear view thereof.

The broken lines shown are for illustrative purposes only and form no part of the claimed design. The dashed portions are for environmental purposes only and form no part of the claimed design. 

The ornamental design for a tractor, as shown and described. 